Light pen

ABSTRACT

An in-put tool for transmitting light pulses to an electronic unit from a light source includes a flexible, fiber-optic, light pipe connected to the unit and having a hollow, tubular light pen affixed around the free terminal end of the pipe. The light pen has a hollow, tubular nose-piece with a hollow, tubular, springpressed plunger therein, the plunger tip contacting the light source and passing light therethrough to the end face of the pipe and thence to the unit. Compression of the plunger causes a magnet to energize a reed switch and close a circuit to the unit.

mag 3,74 g,g3; SEARCH ROOM Uumcu L 1 3,749,932

.Bones 1 1 July 31, 1973 bUBbTlTUTE FOR MISSING XR LIGHT PEN 3,104,9309/1963 Schenzger 178/20 x [76] Inventor: Norman F. Jones, Amherst, NH.Primary Examiner Herman J. Hohouser [22] Filed: June 29, 1972 AssistantExaminer-William J. Smith [2 App] No 267 626 Attorney-Pearson & Pearson[57] ABSTRACT [52] US. Cl 307/112, 178/D1G. 2, 250/227 An in-put toolfor transmitting light pulses to an electronic unit from a light sourceincludes a flexible, fiberoptic, light pipe connected to the unit andhaving a hollow, tubular light pen affixed around the free terminal endof the pipe. The light pen has a hollow, tubular [51] Int. CL. G02b 5/14[58] Field 01 Search 250/227, 217 CR; 178/18, 19, 20, DIG. 2; 340/324 R;307/112 156] References C'ted nose-piece with a hollow, tubular,spring-pressed UNITED STATES PATENTS plunger therein, the plunger tipcontacting the light 3,668,312 6/1972 Yamamoto 340/324 A X source andpassing light therethrough to the end face 3,626,483 12/1971 Whetstone 1178/18 X of th i and thence to the unit Compression of the j l t t t lplunger causes a magnet to energize a reed switch and ewl e a 3,247,3914/1966 Ogle 250/216 close a mum to the 3,199,078 8/1965 Gaffney et al.178/18 X 6 Claims, 8 Drawing Figures 33 I l 11 l PATENTEI] JUL3 1 I975SHEET 1 BF 2 LIGHT PEN Switching means in the Pat. of a switch body witha slidable plunger, or spring-biased push button, the plunger carrying apermanent magnet which magnetically closes a reed switch, are old andwell known. The plunger, or magnet carrier, of such switches, however,has been solid, or dead end; the plunger tips have been solid or cappedand the plunger recess has invariably been dead end, usually to serve asa stop for a coil spring as disclosed in U.S. Pat. No. 3,271,708 toMcCormick of Sept. 6, 1966, US. Pat. No. 3,418,611 to Pounds of Dec. 24,1968, US Pat. No. 3,465,271 to Koepke of Sept. 2, 1969, and US. Pat. No.3,510,607 to Breed of May 5, 1970.

SUMMARY OF THE INVENTION In this invention, the switching means ispreferably also a magnet carrying plunger which is spring compressiblealongside a reed switch. However, the plunger serves the additionalfunction of transmitting light from the open ended, hollow tip thereof,through the axial bore to the polished end face of a fibre-optic lightpipe, leading to an electronic unit responsive to such light pulses.Thus, the light pen of this invention is hollowtubular and mounted toencircle the free terminal end of the light pipe, so that the hollow tipof the plunger may be lightly pressed against the face of a C.R.T.screen to serve as a highly sensitive and responsive input tool forC.R.T. display terminals that require a fast data positioning controlcapability.

It can be used for character sensing and editing operations with mosthigh-speed C.R.T. displays. Depending on C.R.T. editing logic, it can beused to add, delete, correct copy and reposition character and vectordata on the C.R.T. display screen. The pen tip activates the system,while providing a selective signal sensing characteristic to give theoperator precise control of editing functions.

The hand-held pen is coupled by the small, light, flexible fiber-opticlight pipe to a compact electronics unit, for example the Dyno-PakSeries 6000 of Norman- Iones lnc., South Merrimack, N.H., such a unitcontaining a regulated power supply, a signal conditioner and aphotomultiplier, the photomultiplier signal being amplified andconditioned to an output level compatible with most standardized logicsystems.

The light pen of the invention not only has a hollow, tubular tail piecefor receiving the light tube, but also has a hollow, tubular nose piecefor slidably receiving the hollow, tubular plunger, but the coil springmagnet and reed switch are all mounted outside the axial bore of the pento permit light pulses to travel therealong.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of thelight pen of the invention connected by a light pipe to an electronicunit;

FIG. 2 is an enlarged side elevation in half-section of the light pen;

FIG. 3 is a plan view with parts broken away of the device shown in FIG.2;

FIG. 4 is a still further enlarged side elevation of the hollow, tubularplunger of the invention, broken away to show the magnet and magnetgroove;

FIG. 5 is an end view of the plunger shown in FIG. 4 in section on line55 of FIG. 4;

2 FIG. 6 is a form elevation of the hollow, tubular sleeve of theinvention;

FIG. 7 is an end elevation on line 7-7 of FIG. 6 showing the reed switchgroove; and

FIG. 8 is an end elevation on line 8-8 of FIG. 6.

DESCRIPTION OF THE PREFERRED EMBODIMENT end 24, the pipe being about 60inches long. The unit 21 is sensitive to light pulses received throughthe light pipe and received by the polished end face 25 of the free end24, the latter being within the hollow, tubular tail piece 26 of thebody 27 of light pen 28.

The hollow, tubular body of pen 28 also includes a hollow, tubular nosepiece 29 which is telescopably connected at 31 to the tail piece so thatthe two parts are slidably detachable. The nose piece 29 includes aforward axial bore 32 for slidably receiving the hollow, tubular tip 33of the hollow, tubular plunger 34. It also includes a larger,intermediate axial bore 35 for receiving the integral, outwardlyprojecting, annular shoulder 36 of the plunger, or push rod, 34 and thereturn coil srping 37. Nose piece 29 also includes a still largerrearward axial bore 38 for receiving a hollow, tubular sleeve 39,removably seated therein.

The plunger 34 has an elongated magnet groove 41 in the rearwardexterior face thereof, in which the elongated permanent magnet 42 issuitably affixed to extend axially and project outwardly therefrom Thesleeve 39 includes a corresponding elongated magnet groove 43 in theinner face thereof, the groove 43 extending axially alongside anelongated groove 44 in which the reed switch 45 is seated.

It will be seen that when the tip 33 is pressed against a light source,such as a cathode ray tube of a computer terminal, the plunger 34 willbe compressed rearwardly against the bias of spring 37 to move themagnet 42 along its path to close the reed switch 45 and thus complete acircuit to the unit 21. At the same time, any light pulse detected fromthe light source will pass through the axial bore 46 of tip 33 from thefront open end 47 to the rear open end 48 to confront the polished endface 25 of the light pipe and be transmitted thereby to the unit 21.

The switch means 49 formed by the plunger, tip magnet and reed switch isan SPST switch which is normally open with a current capacity of about0.25 amperes. The light pipe 22 is formed of a multiplicity of .003 diameter glass fibers encased in a PVC tube, there being a pair of Tefloninsulated wires also enclosed therein to connect the reed switch 45 tounit 21.

I claim:

1. In combination with an electronic unit, sensitive to light pulses;

a flexible, fiber optic, light pipe having one end connected to saidelectronic unit for transmitting light pulses thereto and having a freeterminal end with a transverse face adapted to receive light;

a light pen mounted on the said free terminal end of said light pipe,said pen including a spring biased, tubular plunger, having an axialbore open at each opposite end and adapted to transmit light from anexterior light source, through said bore, to said end face and switchmeans, associated with said light pen, and operably connected to saidplunger for activating said system when said plunger is pressed againsta light source.

2. A combination as specified in claim 1 wherein:

said plunger includes an integral annular shoulder projecting outwardlytherefrom, said pen includes a removable sleeve encircling said plungerand said pen includes a coil spring encircling said plunger between saidshoulder and sleeve for spring biasing said tubular plunger.

3. A combination as specified in claim 1 wherein:

said pen includes a removable, tubular sleeve slidably receiving saidtubular plunger, said sleeve having an elongated groove containing anaxially extending reed switch and said plunger having an elongatedgroove containing an axially extending permanent magnet, said reedswitch and magnet constituting said switch means.

4. A combination as specified in claim 1 wherein:

said light pen includes a hollow, tubular, two part, telescopable bodycomprising a tubular nose-piece and a tubular tail-piece, saidnose-piece having a forward bore for receiving said plunger, anintermediate larger bore and a rearward, still larger bore and includesa removable tubular sleeve in said rearward bore slidably receiving saidplunger, said sleeve containing a reed switch and said plunger carryinga magnet for actuating said reed switch.

5. A plunger operated magnetic reed switch compris a hollow tubular bodyformed of a hollow tubular nose-piece telescopably mounted on a hollowtubular tail-piece,

a hollow, tubular plunger having a hollow, tubular tip projectingoutwardly from said nose-piece but axially movable inwardly thereofagainst spring pressure,

a flexible, fiber optic, light pipe projecting outwardly from saidtail-piece but extending inwardly and axially of said tail-piece to apolished end confronting the adjacent inner end of said hollow tip toreceive light therefrom, and

switch means in said body, for closing a circuit when said plunger tipis moved inwardly toward the polished end of said light pipe.

6. A combination as specified in claim 5 wherein:

said switch means includes a permanent magnet affixed to the exterior ofsaid hollow tubular plunger within said nose-piece and a reed switchmounted in said body, alongside and outside, the path of travel of saidmagnet, for actuating said reed switch when said plunger is compressed.

k 4 l t i

1. In combination with an electronic unit, sensitive to light pulses; aflexible, fiber optic, light pipe having one end connected to saidelectronic unit for transmitting light pulses thereto and having a freeterminal end with a transverse face adapted to receive light; a lightpen mounted on the said free terminal end of said light pipe, said penincluding a spring biased, tubular plunger, having an axial bore open ateach opposite end and adapted to transmit light from an exterior lightsource, through said bore, to said end face and switch means, associatedwith saiD light pen, and operably connected to said plunger foractivating said system when said plunger is pressed against a lightsource.
 2. A combination as specified in claim 1 wherein: said plungerincludes an integral annular shoulder projecting outwardly therefrom,said pen includes a removable sleeve encircling said plunger and saidpen includes a coil spring encircling said plunger between said shoulderand sleeve for spring biasing said tubular plunger.
 3. A combination asspecified in claim 1 wherein: said pen includes a removable, tubularsleeve slidably receiving said tubular plunger, said sleeve having anelongated groove containing an axially extending reed switch and saidplunger having an elongated groove containing an axially extendingpermanent magnet, said reed switch and magnet constituting said switchmeans.
 4. A combination as specified in claim 1 wherein: said light penincludes a hollow, tubular, two part, telescopable body comprising atubular nose-piece and a tubular tail-piece, said nose-piece having aforward bore for receiving said plunger, an intermediate larger bore anda rearward, still larger bore and includes a removable tubular sleeve insaid rearward bore slidably receiving said plunger, said sleevecontaining a reed switch and said plunger carrying a magnet foractuating said reed switch.
 5. A plunger operated magnetic reed switchcomprising: a hollow tubular body formed of a hollow tubular nose-piecetelescopably mounted on a hollow tubular tail-piece, a hollow, tubularplunger having a hollow, tubular tip projecting outwardly from saidnose-piece but axially movable inwardly thereof against spring pressure,a flexible, fiber optic, light pipe projecting outwardly from saidtail-piece but extending inwardly and axially of said tail-piece to apolished end confronting the adjacent inner end of said hollow tip toreceive light therefrom, and switch means in said body, for closing acircuit when said plunger tip is moved inwardly toward the polished endof said light pipe.
 6. A combination as specified in claim 5 wherein:said switch means includes a permanent magnet affixed to the exterior ofsaid hollow tubular plunger within said nose-piece and a reed switchmounted in said body, alongside and outside, the path of travel of saidmagnet, for actuating said reed switch when said plunger is compressed.